MICROPHONE JARGON CAN BE CONFUSING. LEARN WHAT THINGS LIKE POLAR PATTERNS AND PHANTOM POWER ARE.
3-TO-1 RULEWhen using multiple microphones, the distance between them should be at least three times the distance to the sound source. An example: Two mics placed one foot away from a drum should be spaced three feet apart from each other.
AMBIENCENot the cozy vibe in the studio, this refers to room acoustics or natural reverberation of a space.
BLEED, LEAKAGE, OR SPILLPickup of an instrument by a microphone intended to capture an- other sound source. Normally, your engineer will want to avoid it, but creative leakage can also add a live feeling to a recording.
CAPSULEThe part of a microphone where all the magic happens. It’s inside here where a transducer, or element, converts acoustic energy (sound waves) into an electrical signal. Different mics (dynamic, condenser, ribbon) use different types of transducers.
FEEDBACKYou’re no doubt familiar with this squelching sound, but what causes a PA system howl? Feedback occurs when a microphone picks up amplified sound from a loudspeaker connected to the same mic. This creates a re-amplified loop that eventually will sonically pierce your skull. A guitarist might love it. Your livestream audience likely does not.
FREQUENCY RESPONSEHow a microphone responds to various sound frequencies plotted in decibels and hertz. A flat frequency response means a mic handles all frequencies the same. Using a mic with frequency response tailored to your source will give you the most natural sound. An example: The SM7B has a smooth, wide response that tappers off at the higher frequencies to give you that rich ‘podcast voice’ you’ve always craved.
INVERSE SQUARE LAWYou don’t need a degree in physics to understand this concept. It sim- ply means that direct sound levels increase (or decrease) by about 6 dB when you double (or halve) the distance between a source and microphone. It also underscores how important mic placement is!
ISOLATIONFreedom from leakage or a mic’s ability to reject unwanted sounds. Splendid, splendid isolation ...
PHANTOM POWERMan, their second album was epic! Oh, we’re not talking about the band? In that case, this refers to the extra DC juice (normally 48 volts) supplied by a preamp or mixer via regular XLR cables to power condenser mics with active transducers. It gets its ghostly name from the fact that it simply passes through passive dynamic mics plugged into the same board without affecting them. Warning! Phantom power can blow out passive ribbon mics. Active ribbon mics, however, require it.
PHASE CANCELLATIONThis occurs when using more than one mic on a single source and the waveforms of similar audio signals don’t match up exactly when ombined. Being out of phase will make your audio sound wimpy and pathetic.
POTENTIAL ACOUSTIC GAIN (PAG)This is the amount of gain that a sound system can achieve at or just below the point of feedback.
POLAR PATTERNS (MIC DIRECTIONALITY)A graph showing how the sensitivity of a microphone varies with the angle of the sound source, at a particular frequency. Examples of polar patterns are unidirectional (including cardioid, supercardioid, hypercardioid), bidirectional (figure eight) and omnidirectional.
PRE OR PREAMPA microphone preamplifier simply boosts a weaker mic signal be- fore it goes into a console for mixing and recording. For reference, a typical mic level signal is a meager 2 millivolts, whereas pro audio ‘line level’ signals operate at 1.28 volts.
PROXIMITY EFFECTThe increase in bass occurring with most unidirectional micro- phones when they are placed close to an instrument or vocalist (within 1 ft). Does not occur with omnidirectional microphones.
ROLL-OFFA gradual decrease in response below or above some specified frequency. This can be quite handy if you want to reduce bleed from the bass drum (use a mic with low roll-off) or your cymbals (use a mic with high roll-off).
SOUND PRESSURE LEVEL (SPL)The acoustic intensity of a sound wave. Or how loud something is measured in decibels. It’s important to keep this in mind when matching gear to the various parts of the drum kit you’re miking. Generally speaking, dynamic mics can handle higher SPL.
XLRThe most common form of microphone cable connector for pro audio. An XLR plug has three pins, ensuring the signal is balanced, which helps reduce unwanted noise when using longer cables.
